Ouji-sama wa Ohime-sama [English], by Kobamiso
That’s an interesting combination, to me.
– The makings of vanilla, a childhood friend in love with her only slightly older male friend, she was a tomboy, now she’s a slender babe, her love is confessed, and accepted (but is it reciprocated? Unclear.)
– And powerful sex with borderline verbal abuse, that would have been degrading and reeked of corruption in any other setup.
Not bad, not bad at all
Well, perhaps it’s best to let you see for yourselves, I’d say it’s worth a look at the very least
Thanks to Desudesu and his commissioner!
And now, the download & gallery links 
Open the Complete Pictures Gallery
Download the Free Hentai Manga in a Zip file
(31 MB, 26 pictures, English)
Or you can also use the Alternative:
Zip Mirror #1 – or – Zip Mirror #2 – or – Zip Mirror #3
Personally not sure whether I’d class this as “Vanilla”. At least Kouta and Hajime have awakened to hitherto-unexpressed feelings towards each other, and the resulting happy sexy fun time could be considered for the most part consensual. But it could be equally argued that for Hajime, it’s a case of:

Yeah, the reciprocal nature of love was unclear. But, well, matter of feeling, here. There was this prince thingy, the long lasting affection, feeling like one has to rise to the challenge of being loved. That was moving, to me.
I may be wrong, but I made that personal POV call, simply ^^
Another fire started by smoking in bed.
Damn Right!